Analysis of xx-top500-181-base.sdk

Contents

Original Sudoku

level: medium

Original Sudoku

position: 3.....67....5.1....4.......2......856.1.3..............852.........6.3........... initial

Autosolve

position: 35948267182657143914739652823461..856.18352..5.8.24163.85243.16.12.6835..6315.8.2 autosolve
Autosolve

Pair Reduction Variants

Pair Reduction Analysis

Pair Reduction Analysis

The following important HDP chains were detected:

* DIS # A8: 7,9 => CTR => A8: 4
* PRF # A8: 4 => SOL
* PRF # A9: 7,9 => SOL
* DIS # A9: 4 => CTR => A9: 7,9
* DIS # A8: 7,9 => CTR => A8: 4
* PRF # A8: 4 => SOL
* PRF # A9: 7,9 => SOL
* DIS # A9: 4 => CTR => A9: 7,9
* PRF # A8: 4,7 => SOL
* DIS # A8: 9 => CTR => A8: 4,7
* PRF # A9: 4,9 => SOL
* DIS # A9: 7 => CTR => A9: 4,9
* CNT  12 HDP CHAINS /  12 HYP OPENED

See Appendix: Full HDP Chains for full list of HDP chains.

Pair Reduction

Pair Reduction

The following important HDP chains were detected:

* DIS # A8: 7,9 => CTR => A8: 4
* PRF A8: 4 => SOL
* STA A8: 4
* CNT   2 HDP CHAINS /   1 HYP OPENED

See Appendix: Full HDP Chains for full list of HDP chains.

Details

Positions

3.....67....5.1....4.......2......856.1.3..............852.........6.3........... initial
35948267182657143914739652823461..856.18352..5.8.24163.85243.16.12.6835..6315.8.2 autosolve
359482671826571439147396528234619785671835294598724163785243916412968357963157842 solved

Classification

level: medium

Pairing Analysis

--------------------------------------------------
* PAIRS (13)
B5: 7,9
B6: 7,9
F4: 7,9
D6: 7,9
G4: 7,9
H5: 4,9
I5: 4,7
A7: 7,9
D8: 7,9
F9: 7,9
G7: 7,9
I8: 4,7
H9: 4,9

--------------------------------------------------
* CONSTRAINT PAIRS (AUTO SOLVE)
H5,I5: 4.. / H5 = 4  =>  0 pairs (X) / I5 = 4  =>  0 pairs (_)
A8,A9: 4.. / A8 = 4  =>  0 pairs (*) / A9 = 4  =>  0 pairs (X)
I8,H9: 4.. / I8 = 4  =>  0 pairs (X) / H9 = 4  =>  0 pairs (_)
A8,I8: 4.. / A8 = 4  =>  0 pairs (*) / I8 = 4  =>  0 pairs (X)
A9,H9: 4.. / A9 = 4  =>  0 pairs (X) / H9 = 4  =>  0 pairs (_)
H5,H9: 4.. / H5 = 4  =>  0 pairs (X) / H9 = 4  =>  0 pairs (_)
I5,I8: 4.. / I5 = 4  =>  0 pairs (*) / I8 = 4  =>  0 pairs (X)
B5,B6: 7.. / B5 = 7  =>  0 pairs (*) / B6 = 7  =>  0 pairs (X)
F4,D6: 7.. / F4 = 7  =>  0 pairs (X) / D6 = 7  =>  0 pairs (_)
G4,I5: 7.. / G4 = 7  =>  0 pairs (*) / I5 = 7  =>  0 pairs (X)
D8,F9: 7.. / D8 = 7  =>  0 pairs (X) / F9 = 7  =>  0 pairs (_)
G7,I8: 7.. / G7 = 7  =>  0 pairs (X) / I8 = 7  =>  0 pairs (_)
F4,G4: 7.. / F4 = 7  =>  0 pairs (X) / G4 = 7  =>  0 pairs (_)
B5,I5: 7.. / B5 = 7  =>  0 pairs (*) / I5 = 7  =>  0 pairs (X)
B6,D6: 7.. / B6 = 7  =>  0 pairs (X) / D6 = 7  =>  0 pairs (_)
A7,G7: 7.. / A7 = 7  =>  0 pairs (*) / G7 = 7  =>  0 pairs (X)
A9,F9: 7.. / A9 = 7  =>  0 pairs (X) / F9 = 7  =>  0 pairs (_)
D6,D8: 7.. / D6 = 7  =>  0 pairs (*) / D8 = 7  =>  0 pairs (X)
F4,F9: 7.. / F4 = 7  =>  0 pairs (X) / F9 = 7  =>  0 pairs (_)
G4,G7: 7.. / G4 = 7  =>  0 pairs (*) / G7 = 7  =>  0 pairs (X)
I5,I8: 7.. / I5 = 7  =>  0 pairs (X) / I8 = 7  =>  0 pairs (_)
B5,B6: 9.. / B5 = 9  =>  0 pairs (X) / B6 = 9  =>  0 pairs (_)
F4,D6: 9.. / F4 = 9  =>  0 pairs (*) / D6 = 9  =>  0 pairs (X)
G4,H5: 9.. / G4 = 9  =>  0 pairs (X) / H5 = 9  =>  0 pairs (_)
D8,F9: 9.. / D8 = 9  =>  0 pairs (*) / F9 = 9  =>  0 pairs (X)
G7,H9: 9.. / G7 = 9  =>  0 pairs (*) / H9 = 9  =>  0 pairs (X)
F4,G4: 9.. / F4 = 9  =>  0 pairs (*) / G4 = 9  =>  0 pairs (X)
B5,H5: 9.. / B5 = 9  =>  0 pairs (X) / H5 = 9  =>  0 pairs (_)
B6,D6: 9.. / B6 = 9  =>  0 pairs (*) / D6 = 9  =>  0 pairs (X)
A7,G7: 9.. / A7 = 9  =>  0 pairs (X) / G7 = 9  =>  0 pairs (_)
A8,D8: 9.. / A8 = 9  =>  0 pairs (X) / D8 = 9  =>  0 pairs (_)
D6,D8: 9.. / D6 = 9  =>  0 pairs (X) / D8 = 9  =>  0 pairs (_)
F4,F9: 9.. / F4 = 9  =>  0 pairs (*) / F9 = 9  =>  0 pairs (X)
G4,G7: 9.. / G4 = 9  =>  0 pairs (X) / G7 = 9  =>  0 pairs (_)
H5,H9: 9.. / H5 = 9  =>  0 pairs (*) / H9 = 9  =>  0 pairs (X)
* DURATION: 0:01:04.115040  START: 08:52:42.177187  END: 08:53:46.292227 2017-05-04
* CP COUNT: (35)
* SOLUTION FOUND

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A7,B5,B6,D6,D8,F4,F9,G4,G7,H5,H9,I5,I8)
* 35948267182657143914739652823461..856.18352..5.8.24163.85243.16.12.6835..6315.8.2
* PAIR A7: 7,9 BLK 7
A8: 7,9,4                                # reduction candidate for 7,9
A8: 7,9 => CTR
* 35948267182657143914739652823461..856.18352..5.8.24163.85243.16.12.68354463157892
A8: 4 => SOLVED
* 359482671826571439147396528234619785671835294598724163785243916412968357963157842
A9: 7,9,4                                # reduction candidate for 7,9
A9: 7,9 => SOLVED
* 359482671826571439147396528234619785671835294598724163785243916412968357963157842
A9: 4 => CTR
* 35948267182657143914739652823461..856.18352..5.8.24163.85243.16.12.6835.463157892
* PAIR D8: 7,9 ROW 8
A8: 7,9,4                                # reduction candidate for 7,9
A8: 7,9 => CTR
* 35948267182657143914739652823461..856.18352..5.8.24163.85243.16.12.68354463157892
A8: 4 => SOLVED
* 359482671826571439147396528234619785671835294598724163785243916412968357963157842
* PAIR F9: 7,9 ROW 9
A9: 7,9,4                                # reduction candidate for 7,9
A9: 7,9 => SOLVED
* 359482671826571439147396528234619785671835294598724163785243916412968357963157842
A9: 4 => CTR
* 35948267182657143914739652823461..856.18352..5.8.24163.85243.16.12.6835.463157892
* PAIR I8: 4,7 ROW 8
A8: 4,7,9                                # reduction candidate for 4,7
A8: 4,7 => SOLVED
* 359482671826571439147396528234619785671835294598724163785243916412968357963157842
A8: 9 => CTR
* 35948267182657143914739652823461..856.18352..5.8.24163.85243.16912768354.6315.8.2
* PAIR H9: 4,9 ROW 9
A9: 4,9,7                                # reduction candidate for 4,9
A9: 4,9 => SOLVED
* 359482671826571439147396528234619785671835294598724163785243916412968357963157842
A9: 7 => CTR
* 35948267182657143914739652823461..856.18352..5.8.24163.85243.16412968357.6315.8.2
* INCONCLUSIVE
* SAVE PR GRAPH xx-top500-181-base-pr-000.dot
* REASONING
* DIS # A8: 7,9 => CTR => A8: 4
* PRF # A8: 4 => SOL
* PRF # A9: 7,9 => SOL
* DIS # A9: 4 => CTR => A9: 7,9
* DIS # A8: 7,9 => CTR => A8: 4
* PRF # A8: 4 => SOL
* PRF # A9: 7,9 => SOL
* DIS # A9: 4 => CTR => A9: 7,9
* PRF # A8: 4,7 => SOL
* DIS # A8: 9 => CTR => A8: 4,7
* PRF # A9: 4,9 => SOL
* DIS # A9: 7 => CTR => A9: 4,9
* CNT  12 HDP CHAINS /  12 HYP OPENED

--------------------------------------------------
* PREPARE PR GRAPH
* PAIR REDUCTION ..
* LEVEL 0 PASS 1 ROUND 1 (AUTO SOLVE) (A7,B5,B6,D6,D8,F4,F9,G4,G7,H5,H9,I5,I8)
* 35948267182657143914739652823461..856.18352..5.8.24163.85243.16.12.6835..6315.8.2
* PAIR A7: 7,9 BLK 7
A8: 7,9,4                                # reduction candidate for 7,9
A8: 7,9 => CTR
* 35948267182657143914739652823461..856.18352..5.8.24163.85243.16.12.68354463157892
A8: 4 => SOLVED
* 359482671826571439147396528234619785671835294598724163785243916412968357963157842
* DURATION: 0:00:01.860714  START: 08:54:01.875703  END: 08:54:03.736417 2017-05-04
* SOLUTION FOUND
* SAVE PR GRAPH xx-top500-181-base-pr-001.dot
* REASONING
* DIS # A8: 7,9 => CTR => A8: 4
* PRF A8: 4 => SOL
* STA A8: 4
* CNT   2 HDP CHAINS /   1 HYP OPENED

Header Info

Top 500 Minimum 17 181

solution: 359482671826571439147396528234619785671835294598724163785243916412968357963157842
info: 1828     FNTWX    S8.f     28961

http://www.sfsudoku.com/su17ExtremeDiff500.txt from http://www.minimumsudoku.com/

Solution

position: 359482671826571439147396528234619785671835294598724163785243916412968357963157842 solved
Solution

See section Pair Reduction for the HDP chains leading to this result.

Appendix: Full HDP Chains

A1. Pair Reduction Analysis

Full list of HDP chains traversed:

* DIS # A8: 7,9 => CTR => A8: 4
* PRF # A8: 4 => SOL
* PRF # A9: 7,9 => SOL
* DIS # A9: 4 => CTR => A9: 7,9
* DIS # A8: 7,9 => CTR => A8: 4
* PRF # A8: 4 => SOL
* PRF # A9: 7,9 => SOL
* DIS # A9: 4 => CTR => A9: 7,9
* PRF # A8: 4,7 => SOL
* DIS # A8: 9 => CTR => A8: 4,7
* PRF # A9: 4,9 => SOL
* DIS # A9: 7 => CTR => A9: 4,9
* CNT  12 HDP CHAINS /  12 HYP OPENED

A2. Pair Reduction

Full list of HDP chains traversed:

* DIS # A8: 7,9 => CTR => A8: 4
* PRF A8: 4 => SOL
* STA A8: 4
* CNT   2 HDP CHAINS /   1 HYP OPENED